Many websites, in particular sites with a registered user base (such as, e.g., online social networks), deliver both dynamic content (such as, e.g., custom content generated or assembled from a database based on user-specific information) and static content (such as, e.g., files made available for download). In order to facilitate dynamic content delivery and implement associated access restrictions, customizations, etc., network requests received by the site are often routed to a front-end processing layer (often written in PHP) that, in turn, communicates with the relevant back-end databases or other repositories (optionally via back-end database applications). The operations performed in the front-end processing layer may be computationally expensive and time-consuming, and, accordingly, care is usually taken to provide sufficient hardware resources to serve the anticipated load of requests from a site's users. However, network requests to a website are not generally limited to end-user visitors, but may also come from third-party websites that retrieve and/or link, in particular, to the static content provided by the sites. For example, files downloadable from a website may show up in the search results of a third-party search engine and be downloadable through the search engine, causing additional network traffic to the site without a corresponding increase in actual site visits. In some circumstances, such indirect traffic can grow to a level that puts a severe drain on system resources, slowing down request handling for all users and/or reaching maximum system capacity.